• Alan Shepard’s take-off. It was near the end of the school year and we had a TV in the class. I remember thinking, as I watched the lift-off, that this was real!
• JFK’s assassination. I’ve posted here several accounts of that; suffice to say that I was in the hospital at the time and was thus just watching TV all day - there was an initial announcement that the President had been shot, and video caught up a bit later with the first video I remember being rather chaotic footage from outside of Parkland Hospital. The next few days were a collage of events.
• A friend and I were entering The Groove record shop when another friend came running out. He was upset because his sister was a student at UT and someone had the campus pinned down, shooting people from the Tower. We went in and watched the owner’s TV for a bit. Not much to see, but we were definitely buzzed.
• At a high school football game, word spread that Jimi Hendrix was dead. I was in the gym parking lot when someone told my group. I don’t remember anyone acting particularly bereaved, but we were generally a bit shocked.
• In the U’Tote’Em at the corner of Drexel and Westheimer, in Houston, I was buying a case of beer when Neil Armstrong made his first footstep on the Moon. I watched it on a TV the clerk had up on the counter. My friends out in the car wanted to know what took me so long (they thought I might’ve been nailed for an ID).
• I was in my high school’s political science class when someone told us about the National Guard shootings at Kent State. We were stunned, and really just talked about it, then wandered off to get hard news.
• Hitchhiking down Highway 1 in Northern California, I got picked up by a guy from Berkeley (in a VW van, of course). Listening to the radio, we heard that the NY Times had published a secret report about the Vietnam war. It was all very confusing at first, but we knew it was something big. This was the start of the Pentagon Papers saga.
• I was exiting the West Loop at San Felipe (northbound) in the florist’s delivery truck I drove for a living when I first heard the news of the Watergate burglars. I was astounded, but that story took a little while to build up steam.
• My off-and-on-again girlfriend had deigned that I might visit her for a moment at her parent’s house in El Lago, Texas - that’s where I watched President Nixon resign and climb into the helicopter and fly away.
• Visiting a friend’s ranch, I’d run into town (Moshiem, Texas) and picked up the local rag at a tiny grocery store. As I stood in the parking lot, I read a brief story behind which I knew there had to be more. It was a sketchy report of a U.S. Congressman having been killed at an airstrip in Guyana. That was Jim Jones’ Peoples’ Temple debacle coming to light.
• It was very early in the still dark morning, whenever it was in 1980, when I just happened to wake up and turn on the radio in time to catch a snippet telling us that there had been a failed rescue mission aimed at freeing the Tehran hostages, several casualties, more to follow. I was bummed out.
• I had only just started my post-college career when our draftsman came in to my office wide-eyed and said, “Reagan’s been shot!” A senior geologist soon after came to my office, absolutely pissed off, to speculate about the perpetrator. Who could’ve guessed the story behind that one?
• One day I was sitting at my desk, working, when I heard my secretary shriek in the next office. She ran in to tell me that the space shuttle had blown up. I remember thinking that they probably hadn’t even hit the water yet. At lunch I went to the department store across Main Street and stood, in silence, with about 200 other people, watching ~30 televisions replay the explosion video. I went back to my office and cabled the President my condolences and a “stay the course” message of encouragement regarding the space exploration program.
• 9/11 - One of my co-worker’s wife called to tell us that a plane had crashed into the WTC. We turned on the TV in the drilling VP’s office and just sat and watched. As I recall, there was just a video focussed on the tower, with very sparse commentary. Just as my boss, who was in town for the day, entered, the second plane hit. While many of us (including myself) had up to that moment considered it possibly a tragic accident, we all instantly flashed to what it meant when the second plane arrived. Well, after a split-second of cognitave dissonance (Was that an Instant Replay?).
My boss immediately went to another office to call about his return flight that evening and was told that there were three other hijacked flights in the air. He came back and assembled us for the meeting. We hadn’t been at it very long when a geologist came in and told us they’d hit the Pentagon. My boss closed the office and gathered a few of us to come with him to a restaurant to attempt a meeting. After a short while of just watching the big screen TVs there, we adjourned to our District Landman’s house.
There have, of course, been many other events during my life that I recall, but I’ve been trying to honor the OP’s request for those wherein I can truly remember where I was and what I was doing when first alerted that big news was coming down.
Perhaps it’s a generational thing, but I’m struck by how many have mentioned Princess Diana’s death. That never made my 'scope, but then my parents were the age I am now when Jimi Hendrix died, and I’m not sure they noticed that.